Brush holder



p 94 P. B. BURRUS BRUSH HOLDER Fi ed" July 13, 1945 2 Sheets- Sheet 1 INVENTOR PMQ BY ATTORNE pt 2, 1947- 7 RB. BURRUS 2,426,815

- BRUSH HOLDER Filed July 13, 1943 2 Sheets-Sheet 2 FIG.5 I

INVENTOR TTOR EY Patented Sept. 2, 1947 UNITED STATES PATENT OF FlCE BRUSH HOLDER Paul B. Bur-rus, Dayton, Ohio, assignor to Richard .A .Niekamp, doing business as American Aircraft Associates, Dayton, Ohio .Applicationluly is, 1943, Serial No. 494,549.

4 Claims. 1 This invention relates to a brush holder for an electric motor or a generator and more particularly to the mounting and the adjustment I thereof.

An object of this invention is to provide a brush holder that may be adjusted through any predetermined increment and rigidly secured in position as soon as it has been adjusted.

Another object of this invention is to provide a support for a brush holder that may be removed from the .housing or from its supporting portion to remove the brush supported thereby without disturbing the other brushes.

Another object of this invention is to provide adjustable clamping means for securing a brush holder in any adjusted position upon a support that may or may not be mounted for oscillatory adjustment tochange the angular relation of the brush with respect to the commutator segments.

Another object of this invention .is to provide a support for a brush holder that is insulated from the frame of the electrical device and that is provided with means for compensating for changes in the :dimensions of the insulating material.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

In the drawings,

.Figure .1 discloses a brush mounting supporting .a pair ofxbrushes and attached to the end frame of-':a.motor, which end frame, together with some ofthe mounting parts, has been shown in cross section.

Figure 2 discloses the brush holder and a portion of the. support as viewed from one side, with the brush'resting upon a commutator segment or slip ring, as the case may be.

Figure 3 is a side elevational view of the brush retaining. stud or support as it appears before assembly.

Figure 4 is a side elevational view of a slotted bushing provided with a taper, used in securing the stud in position,

Figure 5 is a fragmentary exploded view of a part of the brush supporting assembly.

In the past, numerous types of brush holders have been developed and used on. electric devices such as motors and dynamos or generators. These generally provide for adjustment of the brush with respect to the commutator, so as to properly position the brush and so as to permit adjustment of the. brush to compensate for its we r- The device disclosed herein provides for these adjustments by permitting the .brush holder to be adjusted through any desired increment away from and towards. .thecommutator and for oscillating the brush holder through any desired increment about apivot parallel to the axis of rotation of the armature. Furthermore, the brush holder is secured in any adjusted position by clamping mechanism or locking mechanism that is dependable. efficient and easily construoted.

Referring to the drawings, the reference. charter L11 indicates a frame of an electric motor, dynamo or generator, as the case may be. An armature, that has not been shown, is journalled in the frame In and is provided with a commutator M, as is known to those skilled in the art.

The end frame It is provided withan aperture having a tapered portion 21), a, shoulder 22., .a cylindrical portion 24 and a rabbet 28. This. aperture is used for insulatingly supporting a brush holder supporting member 30. This brush holder supporting member 39 has a hexagonal portion 32 that may represent the cross sectional area of the original stock used in manufacturing this member. The hexagonal portion 32 may be used as a bolt head. One end of member 3.!) is turned in a lathe, or inany other suitable man ner,-so. as to form a ylindrical portion v34 provided with threads 36. The opposite end is formed into a pentagonal cross sectional area forming a plurality of facets 3.8, that are used for attaching the brush holder, as will be described more fully later.

The cylindrical portion 34 projects through the tapered portion of the aperture in end frame ID. This cylindrical portion 34 is surrounded by a cylindrical insulating sleeve 40 positioned within a conical bushing 42;, having a taper reversed to the taper of the tapered portion 20. The conical bushing 42 is provided with a longitudinal, slot 43, permitting expansion and contraction thereof. The large end of the bushing 42 abuts a metallic washer 44. The reduced end of the tapered bushing 42 terminates in spaced relation from the reduced end of the tapered portion 20 of the; aperture in the end frame ID.

A copper contact member 50 is provided with an aperture receiving the cylindrical portion 34. This contact member is provided with a reentrant portion 52 that grips a ring used in connecting pairs of brushesv of the same polarity together. Member 50 makes an electrical contact directly to member 30. Member 50 is seated against .a

metallic washer 62 abutting a shoulder found between the hexagonal portion 32 and the cylindrical portion 34 of member 30. A plurality of insulating discs or washers I are positioned between member 44 and member 50, so as to provide an insulating support for the assembly. An insulating washer I2 is mounted on the opposite end of the cylindrical portion '34 and is seated against a metallic washer I4 abutting a resilient discshaped metallic washer-like member known in the trade as a beville washer "I6 engaging a washer I8, held in position by a lock washer 80 engaging a nut 82, tightened on the end of the cylindrical member 34, so as to hold the assembly in rigid position. In the event any of the members made of insulating material should expand or contract, this is compensated for by the disc-shaped washer member I6 exerting a tightening pressure in spite of the changed dimensions. A cup 90 is pressfitted or snapped into position and seated in the rabbet 26, so as to seal the nut 82 and the parts associated therewith.

In order to adjust the angular position of the brush with respect to the commutator I4, it is merely necessary to remove the cap 90 and loosen the nut 82 to permit rotation or oscillation of member 30 and the parts carried thereby. When the brushes have been adjusted into proper angular position, the nut 82 may be tightened and the cap 90 snapped into position.

The opposite end of member 30 may support one or more brush holders which will now be described. The brush holder may include member I00, having a U-shaped member I02 attached thereto, providing a channel for the brush I04 spring urged by a spring I06 mounted upon a lever I08 attached to a ratchet member IIO, held in a tense position by a suitable spring II2 seated in one of the notches in ratchet member IIO. This assembly is pivotally mounted on a pivot I I4 journalled in an extension I I6 projecting from substantially U-sh'aped channel member H8. The two legs or flanges I20 of the U-shaped channel member I I8 are provided with apertures receiving bolts I22 passing through a cross bar I24 having a channel-shaped cross sectional area, as best seen in Figure 5. The channel-shaped cross bar I24 is provided with a pair of inclined surfaces I26 engaging similar surfaces on 'a'clamping member I28 that is provided with a V-shaped notch or groove seated upon two sides of the pentagonal portion 36 of member 30. The inclined surfaces or side walls I26 have a wedging action when in engagement with the clamping member I20, so as to rigidly wedge clamping member I28 in home position. By loosening the screws or bolts I 22, the brush holders may be adjusted in the direction of the arrow I50, shown in Figure 1, or in the opposite direction, so as to move the brush in a direction parallel to the axis of rotation of the armature.

The distance between the legs I20 is much greater than the distance across member 30 and the corresponding dimension of the clamping member I28. This permits adjustment of the brush holder either away from the commutator, in the direction of the arrow I52 shown in Figure 2, or towards the commutator when moving the brush holder in the direction opposite to the direction of the arrow I52. Thus, it is seen that the brush holder may be positioned in the proper angular relation with respect to the commutator, may be positioned in the proper axial position and it may be positioned in the proper radial position.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described m invention, I claim:

1, A brush supporting assembly for use in an electric machine, said assembly including a retaining member having a cylindrical portion terminating in a threaded end, a split tapered bushing member encircling the cylindrical portion for use in clamping the retaining member to the end frame of an electric machine, said retaining memher being mounted in the end frame for rotary adjustment about the longitudinal axis of the retaining member, the opposite end of the retaining member being provided with a portion having a plurality of facets, a brush holder member having a. fiat surface subtended by a pair of legs spaced further apart than the thickness of the retaining member, said brush holder member having its fiat surface contacting one of the facets for lateral adjustment parallel to the longitudinal axis of the retaining member and for transverse adjustment between the legs in a direction parallel to the plane of said flat surface so that the brush holder may be adjusted in a rotary direction by adjusting the retaining member in the end frame, in a lateral direction by adjusting the brush holder laterally on the retaining member in a direction parallel to the longitudinal axis thereof and in a transverse direction parallel to the flat surface of the brush holder, and means for clamping the brush holder in adjusted position upon the portion of the retaining member having the facets,

2. A brush supporting assembly for use in supporting a brush in fixed relation with respect to the end frame of an electric machine, said brush assembly including a retaining member mounted for rotary adjustment in the end frame of the electric machine, means for rigidly attaching the retaining member in adjusted position upon the end frame, one end of the retaining member being provided with a portion having a plurality of facets, a brush holder member having a flat surface subtended by a pair of legs spaced further apart than the thickness of the retaining member, the brush holder member having its fiat surface adjustably positioned upon one of the facets for lateral adjustment in a direction parallel to the-longitudinal axis of the retaining member and for transverse adjustment between the legs in a direction normal to the longitudinal axis of the retaining member, and means for clamping the brush holder in an adjusted position upon the portion of the member having facets.

3. A brush supporting assembly for use in supporting a brush in fixed relation with respect to the end frame of an electric machine, said brush assembly including a retaining member mounted for rotary adjustment in the end frame, means for rigidly attaching the retaining member in adjusted position upon the end frame of the electric machine, one end of the retaining member having a pentagonal cross sectional area, a brush holder member havin a flat surface subtended by a pair of legs spaced further apart than the thickness of the retaining member, said brush holder member having its flat surface mounted in contact upon one of the facets for lateral adjustment parallel to the longitudinal axis of the retaining member and for transverse adjustment between the legs in a direction normal to the longitudinal axis of the retaining member, clamping means having a V- groove, the sides of the V-groove engaging a pair of facets opposite the side of the pentagonal portion contacting the flat surface of the brush holder, and a' crossbar mounted upon the legs of the brush holder member for holding the clamping member rigidly against the retaining member for holding the brush holder member in adjusted position with respect to the retaining member.

4. A brush supportin assembly for use in supportin a brush in fixed relation with respect to the end frame of an electric machine, said brush assembly including a retaining member, means for rigidly attaching the retaining member to the end frame of the machine, said retaining member including a hexagonal portion, a pentagonal portion projecting from the hexagonal portion, brush holder means, said brush holder means including a portion having a flat surface subtended by a pair of legs, the distance between the legs bein greater than the thickness of the retaining memher to permit adjustment of said means in a direction normal to the longitudinal axis of the retaining member, said means being adjustably mounted for movement in a direction parallel to REFERENCES CITED The following references file of this patent:

UNITED STATES PATENTS are of record in the Number Name Date 589,543 Brown Sept. 7, 1897 686,729 Heidel Nov. 19, 1901 876,998 Priest Jan. 21, 1908 902,424 Loring Oct. 27, 1908 1,362,007 Jungk Dec. 14, 1920 1,477,606 Sutcliffe Dec, 18, 1923 FOREIGN PATENTS Number Country Date 9,373 Great Britain 1904 

